Bangladesh Meteorological Department on Friday advised maritime ports to hoist local cautionary signal number 4 as depression intensified over Bay of Bengal.
Met Office said the deep depression over the northwest Bay and adjoining area moved northeastwards over the same area and was centred at 6am about 445km west-southwest of Chittagong port, 445km west-southwest of Cox's Bazar port, 240km southwest of Mongla port, and 280km southwest of Payra port.
It is likely to move in a northeasterly direction further, it said.
Maximum sustained wind speed within 48km of the deep depression centre is about 50kph rising to 60kph in gusts. Sea will remain rough near the deep depression centre, the bulletin said.
Under the influence of deep depression, the low-lying areas of the coastal districts of Satkhira, Khulna, Bagerhat, Jhalakathi, Pirojpur, Barguna, Patuakhali, Bhola, Barisal, Lakshmipur, Chandpur, Noakhali, Feni, Chittagong and their offshore islands and chars are likely to be inundated by the wind driven surge of three to five feet height above normal astronomical tide.
All fishing boats and trawlers over the north Bay and deep sea have been advised to remain in shelter till further notice, it added.
BDST: 1250 HRS, OCT 23, 2020